The reduction in volume of natural gas due to
the removal of natural gas liquid constituents such as ethane,
propane, and butane at natural gas processing plants.

Natural Gas Processed

Natural gas that has gone through a processing plant.

Natural Gas Processing Plant

A facility designed to recover natural gas liquids from a stream of natural gas which may or may
not have passed through lease separators and/or field separation facilities.
These facilities also control the quality of the natural gas to be marketed.
Cycling plants are classified as natural gas processing plants.

Natural Gas Processed, Total Liquids Extracted, and Extraction Loss Volume:
Form EIA-64A, "Annual Report of the Origin of Natural Gas Liquids Production"
.
Estimated Heat Content of Extraction Loss: Estimated, assuming the makeup to total liquids
production as reported on Form EIA-64A for each State was proportional to the components and
products ultimately separated in the States as reported on the 12 monthly reports on
Energy Information Administration,
Form EIA-816, "Monthly Natural Gas Liquids Report," and
applying the following conversion factors to the individual component and product
production estimates (million Btu extraction loss per barrel of liquid produced): ethane - 3.082;
propane - 3.836; normal butane - 4.326; isobutane - 3.974; pentanes plus - 4.620.

Annual data on nonhydrocarbon gases removed from marketed production–carbon dioxide, helium, hydrogen sulfide, and nitrogen– were reported by state agencies on the voluntary Form EIA-895A through 2010 and were obtained directly from the states or estimated by EIA for 2011-forward.

Extraction loss is the reduction in the volume of natural gas available for disposition resulting from the removal of natural gas liquid constituents at natural gas processing plants. It represents that portion of the "raw" gas stream that is transferred from the natural gas supply chain to the petroleum and natural gas liquids supply chain. Extraction loss does not include the reduction in volume resulting from the removal of nonhydrocarbon constituents or gas used as fuel, vented, flared, or otherwise disposed of within natural gas processing plants. Extraction loss also results in a reduction in the total heat (Btu) content of the natural gas stream equal to the heat content of the liquids extracted.

The Form EIA-64A, "Annual Report of the Origin of Natural Gas Liquids Production," collects data on the volume of natural gas received for processing, the total quantity of natural gas liquids produced, and the resulting shrinkage (defined as extraction loss in this report) from all natural gas processing- and cycling-plant operators. The quantity of natural gas received and liquids produced are reported by state of origin of the natural gas. Shrinkage volumes are calculated and reported by plant operators based upon the chemical composition of the liquids extracted using standard conversion factors specified in the form instructions

To estimate the quantities of individual products extracted in each state, data from the Form EIA-64A survey were used to determine the total liquids production, and data from the Form EIA-816, "Monthly Natural Gas Liquids Report," survey were used to estimate the quantities of the individual products contained in those total liquids.

The Form EIA-816 captures information on the quantity of individual components (i.e., ethane, propane, normal butane, isobutane, and pentanes plus) produced or contained in mixes of plant liquids as determined by chemical analysis. The volumetric ratios of the individual components to the total liquids, as calculated from the 12 monthly Form EIA-816 reports for each state, were applied to the annual total liquids production, as reported on the Form EIA-64A, to estimate the quantities of individual components removed at gas-processing plants.

The heat (Btu) content of liquids extracted is not reported on the Form EIA-64A.
Therefore, in order to estimate the extraction loss heat content, data reported on the
Form EIA-816 were used to determine the individual products contained in the total liquids reported on
Form EIA-64A.

The heat (Btu) content of extracted liquids was estimated by applying conversion factors
to the estimated quantities of products extracted in each state. These conversion factors,
in million Btu per barrel of liquid produced, were ethane, 3.082; propane, 3.836; normal
butane, 4.326; isobutane,3.974; and pentane plus, 4.620. It should be noted that, at the
state level, extraction losses are not necessarily related to state production.

Extraction loss annual data are calculated from filings of Form EIA-64A.

Preliminary extraction loss data are derived from data reported on
Form EIA-816.

Extraction loss volumes for Gulf of Mexico Federal production are included
in the total extraction loss volumes for the States of Alabama, Louisiana,
and Texas.

Monthly data are revised after the publication of the Natural Gas Annual.
Final monthly data are estimated by allocating annual extraction loss data to each month
based on its total natural gas marketed production.